What Do the IP Water and Dust-Proof Ratings Mean?

A lot of modern mobile phones, electronics, and other devices advertise an IP rating to show how waterproof or dustproof the device is. But these IP ratings aren’t generally well explained in the product materials. The IP ratings are designed to inform consumers of the “Ingress Protection” of the device, or how good it is at stopping physical objects and moisture from interfering with the normal operation of the device.

The IP rating format

The IP rating format includes between two and four ratings, although a fifth rating was originally included in the standard it has since been removed. An IP rating starts with “IP” then has two numbers and can optionally include two-letter ratings.

The first two numbers are mandatory and detail the device’s resistance to solid particles and water interfering with the standard operation of the device respectively. The two-letter ratings are optional and are used to detail the size of the object that is protected from interfering with hazardous parts of the device, and supplementary details about the main testing conditions.

A fifth rating used to be included between the letters and numbers, regarding how impact resistant the device was, although this has since been moved out to a separate “IK” rating.

If a number rating is replaced with an “X” this means that the test has not been performed or has been deemed unnecessary for some reason.

Solid particle protection

Solid particle ratings vary from 0 to 6. One and two cover protection against the accidental insertion of a body part into the device. Three and four cover the accidental insertion of smaller tools while five and six detail the device’s resistance to dust.

Rating	Meaning
0	No protection against contact and ingress of objects.
1	Protection from any large surface of the body such as an elbow or back of the hand.
2	Protection for fingers and other similarly sized objects.
3	Protection against the insertion of tools or thick wires.
4	Protection against the insertion of smaller tools such as thin wires, screws, and nails.
5	Small amounts of dust can enter, but not in large enough quantities to interfere with standard operation.
6	Dust is prevented from entering the device entirely.

 

Water protection

The second number refers to the moisture resistance the device has, with ratings ranging from 0 to 9K. One and two cover drips of water, while three to six, 6K and 9K cover protection against running or sprayed water. Seven and eight define the protection against the device being submerged in water. The two K ratings are not specified in the same standard but may be included in some ratings.

Rating	Meaning
0	No water protection.
1	Protection from dripping water from directly above.
2	Protection from water dripping from a 15-degree angle.
3	Protection against water sprayed from an angle up to 60-degrees.
4	Protection from the being splashed with water from any direction.
5	Protection against a standard jet of water.
6	Protection from powerful jets of water.
6K	Protection from powerful jets of water with increased pressure.
7	Protection from immersion in water up to one meter for thirty minutes.
8	Protection from immersion in water to a depth of more than one meter for more than thirty minutes. (The exact test scenario can be set by the manufacturer but generally uses a depth of 3 metres)
9K	Protection against close range, high-temperature, and high-pressure water jets.

Note: While water resistance ratings up to and including IPX6 are cumulative, the submersion ratings IPX7 and IPX8 do not necessarily imply earlier ratings. Devices that meet both splash and submersion requirements should be shown with two ratings separated by a slash e.g. IPX5/IPX7

Additional optional letter ratings

There are eight letters than can optionally be added to an IP rating. A through D cover the size of objects that are prevented from interacting with hazardous parts of the device, with each level implying protection against previous levels. The second set of letters covers the protection of equipment in specific scenarios, but don’t imply any relation to each other.

Rating	Meaning
A	Protection against the back of the hand interacting with a hazardous part.
B	Protection against a finger interacting with a hazardous part.
C	Protection against a tool interacting with a hazardous part.
D	Protection against a wire interacting with a hazardous part.
H	Specific to high voltage apparatus.
M	Specific to the device being in motion during the water test.
S	Specific to the device being stationary during the water test.
W	Specific to weather conditions.